Nebulisers for ventilation machines are well known in the prior art. For example, WO 2005/048982 A2 discloses such a nebuliser. This nebuliser comprises a body having a first connection that comprises two connecting pieces for connecting the nebuliser to an air supply line and an air exhaust line of the ventilation device. Opposite the first connection, the body comprises a second connection that again has two connecting pieces which are to be connected via a Y-piece and two tubes with a line leading to the patient. Two separate flow channels that are connected via a connecting channel are formed in the body, one (first one) of which serves the flow of respiratory air from the air supply line to the patient and the other (second one) of which serves the flow of consumed air from the patient into the air exhaust line. A non-return valve that allows a flow solely in the direction of the patient is disposed in the first flow channel upstream of a connection of a nebulising device to the first flow channel. Furthermore, the nebulising device is coupled perpendicular, similar to a T connection, to the first flow channel, with the aerosol being supplied in a direction perpendicular to the direction of flow in this first flow channel.
The problem with this design is on the one hand that owing to the non-return valve, an element is integrated in the air supply line, i.e. in the line that leads to the patient, which could have serious consequences should it malfunction.
There is on the other hand the problem that the aerosol is introduced into the flow perpendicular to the direction of flow of the respiratory air through the body, and thus a high deposition of the aerosol on the surfaces of the flow channel occurs, which has a high loss associated therewith.
It is known from other fields of technology to prevent deposition of the aerosol on surfaces in particular of the nebulisation chamber in that the nebulising device nebulises in a direction that is parallel to a flow towards the patient. US-A-2003/0072717, for example, discloses an inhalation device wherein a nebulising device is arranged in a closed and bypassed housing. The housing is disposed in a flow channel of the inhalator, which comprises a mouthpiece. The nebulising device thereby nebulises in the direction of the mouthpiece. However, dead volumes, flow resistance by the nebulising device as well as the filling thereof only play minor roles therein. In ventilation machines, however, the nebulisers must meet predefined criteria in this regard. EP-A-1 818 070 also discloses an inhalation therapy device having such a nebulisation direction, in this case, however, for premature babies. The system (requires the patient to be able to breathe on their own and) is specifically adapted to the small line cross-sections with an inner diameter of between 2 mm and 3.5 mm for premature babies such that air may easily pass around the nebulisation device without flow resistance occurring. Furthermore, since the patient is able to breathe on their own, the system operates at a low pressure of up to 15 mbar. Moreover, filling of the nebuliser with a fluid to be nebulised is not necessary or intended when the system is in operation since operation can be interrupted for filling and/or a loss in pressure in the system can be accepted without risk. Therefore, the above-described and comparable systems from the prior art were not transferable for use in ventilation machines.